DETERMINATION OF THE OPTIMUM MEDIUM FORMULATION FOR THE GROWTH OF INDIGENOUS MICROBES FOR THE BIOSTIMULATION PROCESS IN THE APPLICATION OF MICROBIAL ENHANCED OIL RECOVERY (MEOR) IN OIL WELLS IN JAMBI.

• Main Author: Jefferson Setiawan, Christian
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/84606
• Institution: Institut Teknologi Bandung

Based on data from British Petroleum, throughout 2022, Indonesia produced 31.4 million tons of crude oil, while the consumption of crude oil reached 69.7 million tons. Therefore, the production of crude oil in Indonesia needs to be increased to reduce dependence on crude oil imports. One way to increase crude oil production is through Microbial Enhanced Oil Recovery (MEOR). Biostimulation in the MEOR process is an action to add nutrients, such as carbon (c), nitrogen (N), and phosphorus (P) to stimulate the growth of indigenous microbes. Indigenous microbes will produce metabolites in the reservoir that will improve the physicochemical characteristics of crude oil to increase oil production to the surface. This study aims to optimize the physicochemical quality of oil wells in Jambi through media nutrition optimization using the response surface methodology (RSM). The medium formulation consists of several nutrients such as: molasses (C source), NPK (N and P source), and DAP (N and P source) to stimulate the growth of indigenous microbes in the reservoir. Laboratory experiments were conducted by observing the total number of bacteria with the Total Plate Count (TPC) method on Nutrient Agar (NA), pH changes, and changes in the emulsification index (E24) in the treatment during 5 days of incubation period. Based on the RSM results, the optimum nutrient concentration that can increase the number of cells and increase E24 is molasses 2.29% (w/v), NPK 0.5% (w/v), and DAP 0.19% (w/v) with a predicted cell count of 1.88 x 108 CFU/mL, pH 6.89, and E24 65%. After validation testing, a cell count of 3.42 x 108 CFU/mL, pH 6.89, and E24 92.45% was achieved, which is in line with the prediction. The interfacial tension (IFT) was measured on day 0 at 34.32 dyne/cm, decreasing on day 5 to 32.12 dyne/cm. The composition of crude oil fractions before and after treatment was analyzed through the SARA test with column chromatography where the concentration of saturated hydrocarbons increased from 33.88% to 44.08%, aromatics decreased from 39.44% to 33.06%, resins decreased from 25.27% to 22.04%, and asphaltenes decreased from 1.38% to 0.82%. This is supported by a decrease in viscosity from 8.87 cP to 0.95 cP. The results of this study show that the medium formulation by adding a concentration of molasses 2.29% (w/v), NPK 0.5% (w/v), and DAP 0.19% (w/v) has the potential for MEOR application in oil wells in Jambi.